Mastering endothelial keratoplasty vol 2

Mehta 1.2.4 Intraocular Lens IOL Implant 5 1.3 Surgical Approach: Specifi c Modifi cations to Standard Techniques Endothelial keratoplasty is the current standard of care for disease

Volume II

Editor

Mastering Endothelial Keratoplasty

DSAEK, DMEK, E-DMEK, PDEK, Air pump-assisted PDEK and others Volume II

ISBN 978-81-322-2819-6 ISBN 978-81-322-2821-9 (eBook)

The use of general descriptive names, registered names, trademarks, service marks, etc in this publication does not imply, even in the absence of a specifi c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use

The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors

or omissions that may have been made

Printed on acid-free paper

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Soosan Jacob

Director and Chief

Dr Agarwal’s Refractive and Cornea Foundation

Dr Agarwal’s Group of Eye Hospitals

Chennai

India

“No matter how far we come, our parents

are always in us.”

-Brad Meltzer

It is my pleasure really to write a few words as a foreword for this two-volume book

on endothelial keratoplasty led by Dr Soosan Jacob As a cornea surgeon for the last

20 years, I have personally experienced the evolution of surgical visual tion of patients with corneal endothelial disease and/or trauma My training and early practice was focused on penetrating keratoplasty It was through the work of great innovators in our fi eld of cornea transplantation surgery that endothelial kera-toplasty techniques were introduced and popularized Endothelial keratoplasty techniques currently account for the majority of cornea transplantation procedures performed in the USA and many other countries around the world The advantages

rehabilita-in safety and accelerated effi cacy with endothelial keratoplasty techniques are mous It only takes one intraoperative suprachoroidal hemorrhage during an open-sky graft, or an inadvertent trauma in a successful penetrating keratoplasty, resulting

enor-in a wound dehiscence and catastrophic enor-intraocular structure(s) expulsion to ciate this

The journey in the development of these techniques has been colorful and rapid!

DLEK was probably the earliest innovation, with DSAEK next, and later, DMEK, PDEK and DMET Dr Jacob has been one of those pivotal innovators and early adaptors, as a keen surgeon and passionate clinician enriching the current status quo of cornea surgery with many innovative concepts and techniques Her commitment not only to patient care but also to academic medicine has brought to fruition this cornea transplantation “encyclopedia”

Dr Jacob has generously recruited the signifi cant contributions of many other leading experts and innovators from all around the globe, generating a complete journey for the anterior segment surgeon reader through anatomy, history, tech-nique, technology, complications and their management I think the ophthalmic

community is indebted to her for this brilliant text, and I am personally grateful to use it as a reference guide myself!

Enjoy the knowledge, passion and brilliance of our colleagues in action

A John Kanellopoulos, MD Clinical Professor of Ophthalmology, NYU Medical School

New York, NY Medical Director: The Laservision Clinical and Research Institute, Athens, Greece President: The International Society of Refractive Surgery-Partner

of the American Academy of Ophthalmology

The landscape of cornea as a sub-speciality has changed signifi cantly from the past Technology has improved by leaps and bounds and new techniques are constantly evolving Interlinking of technology, newer surgical techniques, and basic research has brought about rapid shifts in our approach to corneal surgery, especially kerato-plasty Lamellar keratoplasty, both anterior and posterior, have shown such improved results that they have become the standard of care The last two decades have seen the introduction of posterior lamellar keratoplasty as well as many changes in the way it has been performed Endothelial keratoplasty has today become the most popular of choices for endothelial dysfunction requiring surgery

In 2011, about half the corneal transplants performed in the USA were Descemet stripping automated endothelial keratoplasty (DSAEK), and in 2012 it overtook penetrating keratoplasty in terms of the number of corneas being used The accep-tance is similar in many other parts of the world The reason DSAEK is fi nding favor with both surgeons and patients is because of the improved recovery times and visual outcomes as well as the numerous intra-operative advantages However, despite the even greater perceived advantages of the two more recent forms of endothelial keratoplasty – Descemet membrane endothelial keratoplasty (DMEK) and Pre-Descemet endothelial keratoplasty (PDEK) – there is still hesitancy on the part of many corneal surgeons to the inclusion of these into their surgical armamen-tarium This is because these are perceived as more challenging techniques with a greater learning curve

This two-volume book on endothelial keratoplasty (EK) serves to fi ll up a uum in this space as there is at present no book that covers all kinds of EK including DSAEK, ultra-thin DSAEK (UT-DSAEK), DMEK, and PDEK It has been aimed

vac-to serve as an excellent guide for DSAEK vac-to both the beginning surgeon as well as those who need a refresher to sharpen their skills further It also at the same time serves as a stepping stone for successfully, and with minimal heartburn, mastering the more challenging newer endothelial keratoplasties, viz., DMEK and PDEK The various minute steps that are essential for these as well as for newer ancillary tech-niques which help make surgery easy such as endoilluminator assisted DMEK (E-DMEK) and the air-pump assisted PDEK have been described in detail The

original pioneers for the various techniques as well as eminent specialists in this area have contributed their knowledge as well as given their tips and tricks for increasing surgical success The two volumes have been designed to comprehen-sively cover the pre-, intra-, and post-operative period The presence of numerous high-quality photographs, illustrations, and linked videos help make understanding easier and make this two volume book a must-have for all corneal surgeons Despite the amount of educational material in it, the size and format has been kept to allow easy reading The electronic format of the book helps carry it around for easy and quick reference at any place or time

I would like to thank many people for making this labor of love possible My co-authors who have contributed so much of their valuable time and effort to writing excellent chapters and have become dear friends; my friends and colleagues for their constant support in innumerable ways, and Saijimol AI for helping me with everyday work that otherwise would have overwhelmed me I would also like to thank Naren Aggarwal and Teena Bedi from Springer for encouraging me to take on this task, for being immensely helpful at every step and for keeping this book to such high standards I would like to thank all my patients from whom I have learnt

so much and all the teachers in my life who have taught me so much I would like

to especially thank my two mentors, Drs Amar and Athiya Agarwal who have pushed me ever forwards and always encouraged me to keep raising the bar further and further, always more than I would think possible for myself I would also like to thank my parents – Mary Jacob and Lt Col Jacob Mathai – for guiding me and molding me into what I am and my brother Alex Jacob and my sister Asha Jacob for always being there for me Finally, I would like to thank Dr Abraham Oomman, my husband, my best friend, my confi dante, and my sounding board for his unfl inching support and constant love, for making me keep at it and complete it, and lastly my children, Ashwin and Riya, who tolerated me throughout and kept me smiling through all the long hours spent

Finally, as Oliver Wendell Holmes said, “Great things in this world depends not

so much on where we stand but which direction we are moving.” This book is an attempt to throw a light to illuminate the path and make it easier to travel I hope you the reader will enjoy this book and glean from it pearls that you will be able to incorporate into your practice

Chennai, India Soosan Jacob

Dr Soosan Jacob, MS, FRCS, DNB, MNAMS is Director & Chief; Dr Agarwal’s

Refractive and Cornea Foundation (DARCF) and Senior Consultant, Cataract and Glaucoma Services, Dr Agarwal’s Group of Eye Hospitals, Chennai, India She is

a noted speaker widely respected for her innovative techniques and management of complex surgical scenarios She conducts courses and delivers lectures in numerous national and international conferences; has been the recipient of IIRSI Special Gold medal, Innovator’s award (Connecticut Society of Eye Physicians), ESCRS John Henahan award for Young Ophthalmologist, AAO Achievement award and two time recipient of ASCRS Golden Apple award

She has special interest in cutting-edge cataract, cornea, glaucoma, and refractive surgery and has won more than 40 international awards for videos on her surgeries, innovations and challenging cases at prestigious international conferences in United States and Europe Her innovations, many of which have won international awards,

include anterior segment transplantation , where cornea, sclera, artifi cal iris, pupil and IOL are transplanted enbloc for anterior staphyloma; suprabrow single stab

incision ptosis surgery to enhance postoperative cosmesis; turnaround techniques

for false channel dissection during Intacs implantation; Glued Endo-Capsular Ring and Glued Capsular Hook for subluxated cataracts; Stab Incision Glaucoma Surgery (SIGS) as a guarded fi ltration surgery technique; Contact lens assisted crosslinking (CACXL) for safely cross-linking thin keratoconic corneas; Endo- illuminator assisted DMEK (E-DMEK) and Air Pump Assisted PDEK for easier

and better surgical results; and the PrEsbyopic Allogenic Refractive Lenticule

(PEARL) Inlay for treating presbyopia She has proposed a new classifi cation of

Descemet’s membrane detachments into rhegmatogenous, tractional, bullous

and complex detachments with a suitable treatment algorithm and a new

tech-nique of relaxing descemetotomy for tractional Descemet’s detachment Her

sur-geries and surgical techniques have often been Editor’s Choice in prestigious International Ophthalmic websites (AAO/ ONE network, ISRS, Eyetube etc) Her

video blog “Journey into the Eye - A surgeon’s Video blog” in the prestigious Ocular

Surgery News, USA features her surgical videos She also has her own surgical

edu-cational YouTube channel: Dr Soosan Jacob with more than 2500 subscribers

Dr Jacob is senior faculty for training postgraduate, fellowship and overseas doctors She has authored more than 80 peer reviewed articles, numerous chapters

in more than 30 textbooks by international publishers, is editor for 15 textbooks in ophthalmology and reviewer for many prestigious journals She has two popular

columns, “Eye on Technology” and “Everything you want to know about” in the prestigious Eurotimes magazine published by ESCRS

She is a committee member of ISRS/AAO Multimedia Library and is on the editorial board of the Ocular Surgery News–Asia Pacifi c Edition, Cataract and Refractive Surgery Today- Europe, Glaucoma Today and the EuroTimes

Magazines Her life and work have been featured on the Ocular Surgery News

cover page, “5Q” interview (prestigious Cataract and Refractive Surgery Today),

“Sound off” column (CRST) and is the fi rst researcher internationally to be viewed in the prestigious CRST “Researcher’s Column.” She can be contacted at

inter-dr_soosanj@hotmail.com

1 Endothelial Keratoplasty Combined with Cataract Extraction 1

J H Woo and J S Mehta

2 Endothelial Keratoplasty in the Setting of a Dislocated

Intraocular Lens (IOL) 15

Paul M Phillips , Vipul C Shah , and Valliammai Muthuappan

3 Endothelial Keratoplasty in Eyes with Glaucoma 39

Mark Gorovoy

4 Complex Scenarios in PDEK 51

Soosan Jacob

5 Postoperative Graft Management in Endothelial Keratoplasty 73

Claudia Perez-Straziota , Karolinne Maia Rocha , and John Au

6 Complications in DSEK: Prevention and Management 97

Amir A Azari and Christopher J Rapuano

7 Preventing and Managing Postoperative Complications

in DMEK Surgery 113

Christopher S Sáles , Zach M Mayko , Mark A Terry ,

and Michael D Straiko

8 Complications of Pre-Descemet’s Endothelial Keratoplasty

(PDEK) 127

Amar Agarwal and Dhivya Ashok Kumar

9 Endothelial Cell Loss After Endothelial Keratoplasty 141

Dagny Zhu and Neda Shamie

10 Graft Survival in Descemet’s Stripping Automated Endothelial

Keratoplasty (DSAEK) 159

Bekerman Jesica , Grandin C Juan , Gordillo H Carlos ,

and Lotfi C Adriana

11 Graft Rejection in Endothelial Keratoplasty 169

Christine Shieh and Alan N Carlson

12 Graft Thickness and Its Relationship to Visual Outcome

in Endothelial Keratoplasty 197

Deepinder K Dhaliwal and Amr M Kouchouk

13 Targeting Emmetropia in Endothelial Keratoplasty 205

Arun C Gulani

14 Rhokinase Inhibitors for Endothelial Decompensation 217

Dhivya Ashok Kumar

Kaiser permanente , Vacaville , CA , USA

Amir A Azari , MD Cornea Service , Wills Eye Hospital, Sidney kimmel

medical college of Thomas Jefferson university , Philadelphia , PA , USA

Gordillo H Carlos , MD Cornea Department, Instituto Zaldivar , Mendoza , Argentina

Alan Carlson Professor, Chief of Corneal and Refractive Surgery

at the Duke Eye Center , Durham , United Kingdom

Deepinder K Dhaliwal , MD, L.Ac University of Pittsburgh School

of Medicine , Pittsburgh , PA , USA

Mark Gorovoy , MD Department of Ophthalmology , University of California , Fort Myers , FL , USA

Arun C Gulani , MD, MS Gulani Vision Institute , Jacksonville , FL , USA

Soosan Jacob , MS, FRCS, DNB Director and Chief, Dr Agarwal’s Refractive and Cornea Foundation , Dr Agarwal’s Group of Eye Hospitals , Chennai , TN , India

Bekerman Jesica , MD Cornea Department , Instituto Zaldivar , Mendoza ,

Argentina

Grandin C Juan , MD Cornea Department, Instituto Zaldivar , Mendoza ,

Argentina

Amr M Kouchouk , MD University of Pittsburgh Medical Center ,

Pittsburgh , PA , USA

Dhivya Ashok Kumar , MD, FICO Dr Agarwal’s Eye Hospital ,

Chennai , TN , India

Zach M Mayko , MS Lions VisionGift , Portland , OR , USA

J S Mehta Singapore National Eye Centre, Duke-NUS Graduate Medical School , School of Material Science & Engineering and School of Mechanical and Aerospace Engineering, Nanyang Technological University , Singapore , Singapore

Valliammai Muthuappan , MD Sightline Ophthalmic Associates ,

Sewickly , PA , USA

Claudia Perez-Straziota , MD Comprehensive Ophthalmology, Cornea, External Disease and Refractive Surgery , Forrest Eye Centers , Gainesville , GA , Georgia

Paul M Phillips , MD Sightline Ophthalmic Associates , Sewickly , PA , USA

Christopher J Rapuano , MD Refractive Surgery Department , Wills eye Hospital, Sifney Kimmel Medical college at Thomas Jefferson University , Philadelphia , PA , USA

Karolinne Maia Rocha , MD, PhD Medical University of South Carolina (MUSC), Storm Eye Institute, Magill Vision Center , Charleston , SC , USA

Christopher S Sáles , MD, MPH Devers Eye Institute , Portland , OR , USA

Vipul C Shah , MD Charlotte Eye Ear Nose & Throat Associates, PA , Charlotte ,

NC , USA

Neda Shamie , MD University of Southern California Eye Institute ,

Los Angeles , CA , USA

Christine Shieh , MD Durham , NC

Michael D Straiko , MD Devers Eye Institute , Portland , OR , USA

Mark A Terry , MD Devers Eye Institute , Portland , OR , USA

J H Woo Singapore National Eye Centre , Singapore , Singapore

Dagny Zhu , MD Ophthalmology Resident, PGY-3 , University of Southern California Eye Institute , Los Angeles , CA , USA

© Springer India 2016

S Jacob (ed.), Mastering Endothelial Keratoplasty,

DOI 10.1007/978-81-322-2821-9_1

Endothelial Keratoplasty Combined

with Cataract Extraction

J H Woo and J S Mehta

1.2.4 Intraocular Lens (IOL) Implant 5

1.3 Surgical Approach: Specifi c Modifi cations to Standard Techniques

Endothelial keratoplasty is the current standard of care for diseases of corneal

endo-thelial dysfunction, having surpassed conventional penetrating keratoplasty in terms

of safety, speed and predictability of visual recovery, tectonic integrity of the globe,

stability of ocular surface and refractive outcomes [ 1 4 ] As the fi eld of endothelial

keratoplasty continues to advance and evolve, the role of combined procedures to

address endothelial dysfunction with coexisting cataract has been studied Heralded

as ‘the new triple procedure’, endothelial keratoplasty combined with cataract

J H Woo

Singapore National Eye Centre , Singapore , Singapore

J S Mehta (*)

Singapore National Eye Centre, Duke-NUS Graduate Medical School , School of Material

Science & Engineering and School of Mechanical and Aerospace Engineering, Nanyang

Technological University , Singapore , Singapore

e-mail: jodhbir.s.mehta@singhealth.com.sg

extraction offers the promise of rapid visual rehabilitation, predictable refractive outcomes, convenience and cost-effectiveness of a one-stage procedure, without the purported risks of increased postoperative complications [ 5 8 ] The decision to pro-ceed with the triple procedure and surgical planning can be complex and necessi-tates careful consideration of the patient’s visual function and requirements, underlying cause of endothelial dysfunction, the presence of any concurrent ocular disease and target refraction Specifi c modifi cations to surgical techniques in phaco-emulsifi cation and endothelial keratoplasty are often required to further optimize visual outcomes and minimize complications

1.2 Considerations for Surgery

1.2.1 Indications

The defi nite indication for endothelial keratoplasty combined with cataract tion is the presence of corneal decompensation, without stromal scarring, and visu-ally signifi cant cataract (Fig 1.1 ) It is important to determine the extent to which the underlying cornea condition and cataract contributes to the patient’s symptoms and reduced vision as well as the longer term effects of cataract surgery on the cor-nea (or vice versa, that of endothelial keratoplasty on the lens clarity)

Any visually signifi cant lens opacity will necessitate cataract extraction, which may be undertaken as a single procedure, if the corneal endothelial reserves are deemed suffi cient; as part of a sequential or staged procedure before or after kerato-plasty; or as part of a triple procedure The main risk of performing cataract extrac-tion alone in such a scenario is that of future endothelial cell loss and resultant corneal decompensation It has been shown that endothelial cell loss occurs at a rate

of 2.5 % per year 10 years after cataract surgery, 2.5–8.0 times the rate in healthy unoperated eyes [ 9 ] Patients with diabetes mellitus [ 10 ], eyes with shorter axial length [ 11 , 12 ] and hard cataracts [ 13 ] are predisposed to increased endothelial

Fig 1.1 A patient with corneal decompensation secondary to Fuchs endothelial dystrophy and visually signifi cant nuclear sclerotic cataract ( a ) Photograph showing corneal edema and nuclear sclerotic cataract ( b ) Magnifi ed view of cornea showing guttata and endothelial pigments

damage during surgery Surgical variables and complications such as prolonged phacoemulsifi cation time [ 11 ], posterior capsule rupture [ 14 ] and postoperative intraocular pressure spike [ 12 ] may further deplete corneal endothelial reserve in an already compromised eye As such, identifi cation of patients at risk of signifi cant endothelial cell loss after cataract surgery alone may aid surgical decision-making Careful counselling of such patients regarding the potential need for endothelial keratoplasty in the event of corneal decompensation in the future cannot be overemphasized

Conversely, for eyes with marked endothelial dysfunction but only incipient ticular opacifi cation, the options include endothelial keratoplasty alone or the triple procedure The main concern with proceeding with endothelial keratoplasty alone is the acceleration of cataract formation [ 15 – 18 ] , not unlike that seen in penetrating keratoplasty [ 19 , 20 ] Price et al., in a retrospective review of 60 phakic eyes which had undergone Descemet stripping endothelial keratoplasty (DSEK), reported a rate

len-of cataract formation len-of 43 % after 3 years len-of follow-up, signifi cantly higher than that of unoperated normal eyes in the same age group [ 16 ] Burkhart et al also reported a 76 % rate of cataract progression in 49 eyes which had undergone Descemet membrane endothelial keratoplasty (DMEK) at the end of 1 year [ 20 ] Both studies identifi ed age as a signifi cant risk factor for cataract formation and cataract extraction after endothelial keratoplasty, with the likelihood of cataract extraction within 3 years increased from 7 % in patients who were 50 years or younger at the time of surgery to 55 % in those over 50 years of age [ 16 ] In a small case review of 12 eyes after phakic Descemet membrane stripping endothelial kera-toplasty (DSAEK), Tsui et al also found a signifi cant difference in the mean ante-rior chamber depth between eyes that developed cataracts and those that did not, with cataract development being associated with a preoperative anterior chamber depth of less than 2.80 mm [ 17 ] Therefore, for younger patients, in whom the pres-ervation of a clear crystalline lens with its accommodative amplitude is favoured, endothelial keratoplasty alone may suffi ce Older patients without visually signifi -cant cataract will need to be counselled regarding the risk of cataract formation and progression after endothelial keratoplasty before an informed choice between pro-ceeding with cataract surgery after keratoplasty or as part of a combined procedure Notably, various groups have reported good clinical outcomes with cataract surgery after endothelial keratoplasty Price et al reported no intraoperative and postopera-tive complications or signifi cant decline in central endothelial cell density in 22 eyes in which cataract extraction was successfully performed after DSEK [ 16 ] Similarly, the feasibility of standard technique phacoemulsifi cation after DMEK has been supported by Dapena et al [ 21 ]

Traditionally, slit-lamp biomicroscopic evidence of microcystic oedema or mal thickening, a central corneal thickness (CCT) measurement of more than

stro-600 μm and low central endothelial cell count by specular microscopy have been accepted as predictors of endothelial failure after cataract surgery [ 22 ] Seitzman

et al., in a large retrospective non-comparative case series of 136 patients with Fuchs endothelial dystrophy who underwent phacoemulsifi cation, recommended increasing the CCT measurement cut-off to 640 μm and even beyond, in view of advancements in cataract surgery techniques which allowed for improved visual

rehabilitation in patients [ 23 ] These factors, together with higher age, presence of morning blur, reduced best-corrected visual acuity (BCVA), decreased contrast sen-sitivity, glare and failure of endothelial cell measurement should sway the corneal surgeon towards offering a triple procedure The limitations of CCT as a sole deter-minant of future need for endothelial keratoplasty, taking into account the normal distribution within the population and diurnal variations, have prompted the search for other novel objective predictors Van Cleynenbreugel et al proposed the use of

in vivo confocal microscopic basal epithelial cell layer backscatter measurement, as

an indicator of corneal hydration status, to predict the need for endothelial plasty after cataract surgery in patients with Fuchs endothelial dystrophy [ 24 ]

kerato-1.2.2 Planned Sequential Surgery or Triple Procedure

Proponents of planned sequential cataract extraction and endothelial keratoplasty are chiefl y concerned with the theoretical risks of increased graft dislocation [ 25 ], instability of newly implanted intraocular lens (IOL) [ 26 ] causing graft damage and the increased infl ammatory response associated with the combined procedure [ 27 ] Similarly, poor visualization of anterior chamber and lens details from bullous kera-topathy have prompted others to recommend performing endothelial keratoplasty

fi rst followed by cataract extraction several months later when corneal clarity has been substantially restored [ 28 ]

However, various groups have since shown that with modifi cations in surgical technique, combined surgery has a good safety profi le with regards to graft disloca-tion and primary graft failure [ 5 ], with no higher risk than performing endothelial keratoplasty alone [ 6 ] In a prospective, non-comparative, interventional case series

of 315 eyes with Fuchs endothelial dystrophy which had undergone either DSAEK alone or triple procedure, Terry et al reported a dislocation rate of 1.8 % for com-bined surgery group compared to 4 % in the DSAEK only group and no case of primary graft failure [ 5 ] Similarly, Chaurasia et al., in a case series of 492 eyes which had undergone DMEK alone or with concurrent cataract surgery, did not fi nd any signifi cant difference in rates of graft failure, air reinjection and endothelial cell loss within 3–6 months between the two groups [ 6 ]

1.2.3 Refractive Targets

In contrast to penetrating keratoplasty, which induces changes in both the anterior and posterior corneal curvature, modern endothelial keratoplasty techniques do not alter the corneal topography signifi cantly [ 29 , 30 ] and hence induce minimal changes to the cylinder or spherical equivalent However, a hyperopic shift of 0.7–1.5 D (median 1.2 D) has been described in DSAEK [ 1 , 7 , 27 , 31 , 32 ] A similar, but smaller, shift of up to 0.9 D can also be expected in DMEK [ 8 33 , 34 ] This effect

is commonly attributed to a more negatively powered posterior corneal curvature

secondary to the non-uniform thickness profi le of the donor lenticule which may be thin centrally but thick in the periphery [ 35 – 37 ]

Therefore, it may be prudent to empirically target a more myopic postoperative refraction between −1.00 and −2.00 D in eyes undergoing combined endothelial keratoplasty and cataract extraction, in order to avoid unintended hyperopic results This principle should also be applied in patients with endothelial dysfunction who are undergoing cataract surgery alone in anticipation of the hyperopic shift associ-ated with endothelial keratoplasty, if required in the future In addition, it is impor-tant to take into account a possible reduction in hyperopic shift over time after endothelial keratoplasty Scorcia et al [ 37 ] reported the average postoperative spherical equivalent changed from −0.31 ± 2.35 D before surgery to 1.03 ± 2.21 D 1 month after surgery, 0.61 ± 2.07 D 3 months after surgery, and 0.31 ± 2.03 D 12 months in 34 eyes after standard DSAEK This progressive change in hyperopic shift was correlated with the overall reduction of corneal thickness, and in particu-lar, with the difference in thickness between central and peripheral cornea Similarly,

in a retrospective observational study of nine eyes post-DSEK, Holz et al [ 38 ] also reported a change in monthly postoperative spherical equivalent of −0.25 D over the initial 100–200 days, secondary to differential donor graft thinning over time Patients should therefore be counselled regarding this possible change in postopera-tive refraction and may need future changes in spectacle correction

Separate strategies in improving refractive outcomes in the new triple procedure have since emerged Bonfadini et al proposed the optimization of IOL constant in which prediction errors were retrospectively calculated for 30 consecutive triple DSAEK procedures performed by a single surgeon and used to calculate the IOL constant for the cohort He reported a reduction of the mean absolute error from

1.09 ± 0.63 D (range, 0.12–2.41 D) to 0.61 ± 0.4 D (range, 0–1.58 D; P = 0.004) and a

signifi cant improvement of refractive accuracy compared to the manufacturer’s IOL constant with such optimization [ 39 ] In response to the expected hyperopic shift from reduced corneal power seen in post-DSAEK eyes, De Sanctis et al adjusted the

K readings by −1.19 D before the IOL calculation They reported a mean absolute prediction error was 0.59 ± 0.42 D (range, 0.05 to −1.52 D) from this approach, com-

pared to 0.86 ± 0.62 D; P = 0.04 unadjusted The postoperative spherical equivalent

fell within ±0.50 D, ±1.00 D and ±2.00 D of the predicted refraction in 55.5 %, 83.3 % and 100 % of cases, respectively They concluded that this led to more accu-rate IOL calculation and predictable refractive error after combined surgery [ 40 ]

1.2.4 Intraocular Lens (IOL) Implant

The effect of IOL design on the outcomes of combined endothelial keratoplasty and cataract surgery has not been well studied There have been concerns regarding the stability of the implanted IOL during combined procedures, in particular, the risks

of lens decentration and dislocation during donor graft insertion and air bubble placement, which may lead to endothelial cell loss This may be further compounded

by intraoperative factors such as an oversized capsulorrhexis, fl uctuations in

anterior chamber dynamics, iris prolapse and a large dilated pupil Notably, Laaser

et al [ 8 ], in a retrospective case series of 61 consecutive eyes which had undergone simultaneous DMEK and cataract surgery, compared the use of a spherical single- piece acrylic intraocular lens and a multi-piece acrylic intraocular lens, but found no signifi cant difference in BCVA, spherical equivalent, endothelial cell density, cen-tral corneal thickness, refractive and topographic cylinder, target refraction as well

as the rebubbling rate between the two designs

The use of toric IOL may be feasible, given the stability of refractive astigmatism after endothelial keratoplasty [ 41 ] Scorcia et al [ 42 ] reported a case in which simultaneous DSAEK and cataract surgery with implantation of a customized hydrophilic acrylic bitoric IOL was performed in a patient with a failed penetrating keratoplasty graft, secondary cataract and high astigmatism A BCVA of 20/20 was achieved at 6 months, with improvement in refraction from −3.00/−8.50 × 12 preop-eratively to +0.25/−1.00 × 10 postoperatively Wavefront analysis and internal topography map showed only 4° of IOL rotation from the intended axis while there was 15 % endothelial cell loss from the baseline value However, such an approach may be limited by diffi culty in obtaining precise biometric measurements in the presence of corneal oedema, in addition to any surgically induced astigmatism Higher order aberrations and back scatter associated with endothelial kerato-plasty [ 43 – 45 ] essentially precludes the implantation of multifocal IOLs Similarly, the relative lack of refractive predictability (still, at present stage) in endothelial keratoplasty makes accommodative IOLs, for which achieving postoperative emme-tropia is crucial, a poor option when considering combined surgery

Opacifi cation of the IOL is a potential complication after endothelial plasty [ 46 , 47 ]

Patryn et al fi rst reported three cases of membranous opacifi cation over the rior surface of previously implanted foldable acrylic IOL 7–18 months after DSEK [ 46 ] Fellman et al [ 47 ] went further to examine the ultrastructure and histology of the deposits found on a hydrophilic acrylic IOL 9 months after DSEK Light microscopy revealed the presence of granular deposits densely distributed in a round pattern within the margins of the anterior capsulorrhexis These lesions also stained positive for calcium using alizarin red and von Kossa methods The aetiology of IOL opacifi -cation is unknown but has been postulated to be the result of calcifi cation caused by IOL-air contact as well as metabolic and/or infl ammatory changes associated with air injection and surgical manipulation Nevertheless, any opacifi cation of the IOL is likely to be visually signifi cant, with high degree of light scattering [ 47 ] These lesions may not be amenable to medical treatment, and often require an exchange of the IOL

ante-1.3 Surgical Approach: Specifi c Modifi cations to Standard Techniques in Combined Surgery

We routinely perform combined endothelial keratoplasty and cataract surgery under general or local (peribulbar) anaesthesia This is to ensure patients’ comfort and

cooperation due to the anticipated longer duration of surgery and precise intraocular manipulation involved Although, topical anaesthesia has been advocated by some authors [ 48 – 50 ], this may not be ideal for surgeons on the learning curve or patients who may be anxious or are unlikely to cooperate fully during the course of surgery The cataract surgery component of the operation takes precedence over endothelial keratoplasty, to avoid unnecessary trauma to the cornea graft Visualization in eyes with severe corneal oedema and bullous keratopathy can be improved by performing epithelial debridement (Fig 1.2 ) A standard 4.5 mm scleral tunnel and paracentesis incision wound are created, with emphasis on making the paracentesis shorter and more vertically orientated This is done to prevent the graft from occluding the para-centesis and allow easier injection of air in the later stages of surgery Visualization of anterior chamber and lens may be further enhanced with the use of trypan blue dye.Cohesive ophthalmic viscoelastics (OVDs), such as Healon (Abbott Medical Optics Inc., Santa Ana, California, USA), are recommended during cataract surgery Although dispersive OVDs are used in standard cataract surgery, the risk of viscoelas-tic retention may cause subsequent problems in combined surgeries Major concerns about retained viscoelastics impeding graft adhesion (with resultant dislocation) and interfering with interface clarity have been voiced by several authors [ 6 , 25 , 51 – 53 ]

To date, there is no large prospective randomized study aimed at evaluating the role of viscoelastic in graft adherence and dislocation However, Terry et al have suggested the safety of Healon in combined surgeries after reporting a lower rate of graft dislocation than all other published data in which Healon was not used before donor insertion This was further substantiated by full graft attachment without any viscoelastic in the interface immediately after surgery, amongst the eyes in which graft dislocation occurred subsequently [ 5 ] As such, meticulous and thorough removal of viscoelastics (including behind the IOL) at the end of cataract surgery

Fig 1.2 Epithelial debridement to improve visualization in severe bullous keratopathy

remains a crucial step in the new triple procedure However, we prefer to perform the descemetorhexis under air following Healon removal (Fig 1.3 ).

This allows excellent visualization and better control of the continuous ear tear of the Descemet membrane, due to the enhanced surface tension, from the air-tissue interface on the posterior corneal surface Also a complete air fi ll in the anterior chamber confi rms the complete removal of viscoelastic following IOL insertion [ 54 ]

In order to prevent IOL prolapse from the capsular bag and into the anterior ber, especially after the donor lenticule has already been inserted (Fig 1.4 ), we typi-

Fig 1.3 Descemetorhexis performed under air provides excellent visualization and surgical

con-trol A complete air fi ll confi rms the removal of all viscoelastic

Fig 1.4 Insertion of the donor lenticule using the Endoglide Ultrathin

cally undersize our capsulorrhexis to 4–5 mm or smaller (Fig 1.5 ) To ensure additional stability of the IOL in preparation for graft insertion, a miotic agent such

as carbachol 0.01 % is injected intracamerally to constrict the pupil This manoeuvre also serves to prevent iris prolapse and inadvertent insertion of the graft into the pos-terior chamber We routinely perform an inferior peripheral iridectomy in all cases to avoid the risk of pupil block (Fig 1.6 ) Lastly, all wounds are sutured to ensure air and water tightness, to avoid problems of air leakage and hypotony (Fig 1.7 )

1.4 Outcomes

Current literature on the outcomes of combined endothelial keratoplasty and ract surgery is promising but limited Covert et al [ 7], in prospective non- comparative case series of 21 eyes of 21 consecutive patients with Fuchs endothelial

Fig 1.5 ( a ) The capsulorrhexis is undersized to prevent IOL prolapse out of the capsular bag

( b ) The arrows indicate the margins of the capsulorrhexis

Fig 1.6 ( a ) Creation of an inferior peripheral iridectomy to prevent pupil block ( b ) Inferior

surgi-cal iridectomy as indicated by the arrow

dystrophy and coexisting senile cataract who underwent combined DSAEK and phacoemulsifi cation with 6 months of follow-up, concluded that the procedure pro-vides rapid visual rehabilitation with predictable refractive outcomes The average preoperative and 6-month postoperative BCVA was 20/68 ± 1.7 lines (mean ± stan-dard deviation) and 20/34 ± 1.1 lines, respectively, with over 90 % of eyes (19 out of 21) having achieved a BCVA of 20/40 or better They reported three eyes with donor corneal lenticule dislocation on the fi rst postoperative day, while two of these went

on to have recurrent dislocation which necessitated a repeat DSAEK The authors attributed the observed dislocation rate to the learning curve associated with the procedure and have recommended further refi nement of surgical techniques, such as corneal venting incisions, peripheral corneal scraping and longer air tamponade, to improve lenticule adherence Other complications in the series included acute graft rejection (three eyes) and pupillary block glaucoma (two eyes)

Terry et al [ 5 ], who performed combined DSAEK and phacoemulsifi cation on

225 eyes with Fuchs endothelial dystrophy and cataract, reported a dislocation rate

of 1.8 % (four eyes) with no case of iatrogenic primary graft failure In terms of visual outcomes, the BCVA improved from an average of 20/52 preoperatively to 20/31 at 6 months after surgery, representing an average gain of 2 Snellen lines

( P < 0.001) Of these, 93 % of eyes achieved a BCVA of 20/40 or better The group

went further to evaluate the rate of donor endothelial cell loss and reported a mean loss of 32 ± 14 % and 32 ± 15 % at 6 and 12 months, respectively There was no sig-nifi cant cell loss between the 6- and 12-month period and between combined sur-gery and DSAEK only groups

Combined DMEK and cataract surgery (coined ‘triple-DMEK’) represents another step forward in the evolution of the triple procedure, as the replacement of diseased host endothelium without additional donor stromal tissue provides more rapid visual recovery and lower risks of graft rejections [ 55 , 56 ] Chaurasia et al

Fig 1.7 Full air tamponade after donor lenticule insertion All wounds have been sutured to

pre-vent air leakage and hypotony

[ 6 ] reported an improvement in median BCVA from 20/40 to 20/20 in 180 eyes with Fuchs endothelial dystrophy which had undergone triple-DMEK, after excluding eyes with pre-existing retinal and optic nerve pathology The group also found an air reinjection rate of 29 %, in addition to a median endothelial cell loss

of 25 % at 6 months, with 3.5 % of eyes having primary graft failure Similarly, Laaser et al [ 8 ] reported satisfying results in terms of visual outcomes for 61 eyes which had undergone triple-DMEK In their series, the BCVA improved from 0.6 ± 0.23 logMAR preoperatively to 0.19 ± 0.22 logMAR at 6 months after sur-gery, with 81.4 % of eyes reaching a BCVA of 20/40 or better Notably, the mean endothelial cell loss was 40 % after 6 months while 73.8 % of eyes required at least one air injection postoperatively, comparable to reinjection rates reported for DMEK alone [ 33 ]

4 Eye Bank Association of America 2008 eye banking statistical report Washington, DC: Eye Bank Association of America; 2009

5 Terry MA, Shamie N, Chen ES, et al Endothelial keratoplasty for Fuchs’ dystrophy with ract: complications and clinical results with the new triple procedure Ophthalmology 2009;116:631–9

6 Chaurasia S, Price Jr FW, Gunderson L, et al Descemet’s membrane endothelial keratoplasty: clinical results of single versus triple procedures (combined with cataract surgery) Ophthalmology 2014;121:454–8

7 Covert DJ, Koenig SB New triple procedure: Descemet’s stripping and automated endothelial keratoplasty combined with phacoemulsifi cation and intraocular lens implantation Ophthalmology 2007;114:1272–7

8 Laaser K, Bachmann BO, Horn FK, et al Descemet membrane endothelial keratoplasty bined with phacoemulsifi cation and intraocular lens implantation: advanced triple procedure

14 Yamazoe K, Yamaguchi T, Hotta K, et al Outcomes of cataract surgery in eyes with a low corneal endothelial cell density J Cataract Refract Surg 2011;37:2130–6

15 Price MO, Price Jr FW Cataract progression and treatment following posterior lamellar toplasty J Cataract Refract Surg 2004;30:1310–5

16 Price MO, Price DA, Fairchild KM, et al Rate and risk factors for cataract formation and extraction after Descemet stripping endothelial keratoplasty Br J Ophthalmol 2010;94:1468–71

17 Tsui JYM, Goins KM, Sutphin JE, et al Phakic Descemet stripping automated endothelial keratoplasty: prevalence and prognostic impact of postoperative cataracts Cornea 2011;30:291–5

18 Burkhart ZN, Feng MT, Price Jr FW, et al One-year outcomes in eyes remaining phakic after Descemet membrane endothelial keratoplasty J Cataract Refract Surg 2014;40:430–4

19 Payant JA, Gordon LW, VanderZwaag R, et al Cataract formation following corneal tation in eyes with Fuchs’ endothelial dystrophy Cornea 1990;9:286–9

20 Martin TP, Reed JW, Legault C, et al Cataract formation and cataract extraction after ing keratoplasty Ophthalmology 1994;101:113–9

21 Dapena I, Yeh RY, Quilendrino R, et al Surgical step to facilitate phacoemulsifi cation after Descemet membrane endothelial keratoplasty J Cataract Refract Surg 2012;38:1106–7

22 American Academy of Ophthalmology Anterior Segment Panel, Preferred Practice Pattern Guidelines Cataract in the adult eye San Francisco: American Academy of Ophthalmology; 2001

23 Seitzman GD, Gottsch JD, Stark WJ Cataract surgery in patients with Fuchs’ corneal phy: expanding recommendations for cataract surgery without simultaneous keratoplasty Ophthalmology 2005;112:441–6

24 Van Cleynenbreugel H, Remeijer L, Hillenaar T Cataract surgery in patients with Fuchs’ endothelial corneal dystrophy: when to consider a triple procedure Ophthalmology 2014;121:445–53

25 Melles GR Posterior lamellar keratoplasty: DLEK to DSEK to DMEK Cornea 2006;25:879–81

26 Gorovoy MS Descemet-stripping automated endothelial keratoplasty Cornea 2006;25:886–9

27 Chang ST, Yamagata AS, Afshari NA Pearls for successful cataract surgery with endothelial keratoplasty Curr Opin Ophthalmol 2014;25:335–9

28 Terry MA Endothelial keratoplasty: clinical outcomes in the two years following deep lar endothelial keratoplasty (an American Ophthalmological Society thesis) Trans Am Ophthalmol Soc 2007;105:530–63

29 Heidemann DG, Dunn SP, Chow CY Comparison of deep lamellar endothelial keratoplasty and penetrating keratoplasty in patients with Fuchs endothelial dystrophy Cornea 2008;27:161–7

30 Rao SK, Leung CK, Cheung CY, et al Descemet stripping endothelial keratoplasty: effect of the surgical procedure on corneal optics Am J Ophthalmol 2008;145:991–6

31 Koenig SB, Covert DJ, Dupps Jr WJ, et al Visual acuity, refractive error, and endothelial cell density six months after Descemet stripping and automated endothelial keratoplasty (DSAEK) Cornea 2007;26:670–4

32 Jun B, Kuo AN, Afshari NA, et al Refractive change after descemet stripping automated endothelial keratoplasty surgery and its correlation with graft thickness and diameter Cornea 2009;28:19–23

33 Price MO, Giebel AW, Fairchild KM, et al Descemet’s membrane endothelial keratoplasty: prospective multicenter study of visual and refractive outcomes and endothelial survival Ophthalmology 2009;116:2361–8

34 Ham L, Dapena I, Moutsouris K, et al Refractive change and stability after Descemet brane endothelial keratoplasty Effect of corneal dehydration-induced hyperopic shift on intra- ocular lens power calculation J Cataract Refract Surg 2011;37:1455–64

35 Dupps Jr WJ, Qian Y, Meisler DM Multivariate model of refractive shift in Descemet-stripping automated endothelial keratoplasty J Cataract Refract Surg 2008;34:578–84

36 Hwang RY, Gauthier DJ, Wallace D, et al Refractive changes after descemet stripping thelial keratoplasty: a simplifi ed mathematical model Invest Ophthalmol Vis Sci 2011;52:1043–54

37 Scorcia V, Matteoni S, Scorcia GB, et al Pentacam assessment of posterior lamellar grafts to explain hyperopization after Descemet’s stripping automated endothelial keratoplasty Ophthalmology 2009;116:1651–5

38 Holz HA, Meyer JJ, Espandar L, et al Corneal profi le analysis after Descemet stripping thelial keratoplasty and its relationship to postoperative hyperopic shift J Cataract Refract Surg 2008;34:211–4

39 Bonfadini G, Ladas JG, Moreira H, et al Optimization of intraocular lens constant improves refractive outcomes in combined endothelial keratoplasty and cataract surgery Ophthalmology 2013;120:234–9

40 de Sanctis U, Damiani F, Brusasco L, et al Refractive error after cataract surgery combined with descemet stripping automated endothelial keratoplasty Am J Ophthalmol 2013;156:254–9

41 Terry MA, Shamie N, Chen ES, et al Precut tissue for Descemet’s stripping automated thelial keratoplasty: vision, astigmatism, and endothelial survival Ophthalmology 2009;116:248–56

42 Scorcia V, Lucisano A, Beltz J, et al Combined Descemet-stripping automated endothelial toplasty and phacoemulsifi cation with toric intraocular lens implantation for treatment of failed penetrating keratoplasty with high regular astigmatism J Cataract Refract Surg 2012;38:716–9

43 van Dijk K, Droutsas K, Hou J, et al Optical quality of the cornea after Descemet membrane endothelial keratoplasty Am J Ophthalmol 2014;158:71–9

44 Patel SV, Baratz KH, Maguire LJ, et al Anterior corneal aberrations after Descemet’s stripping endothelial keratoplasty for Fuchs’ endothelial dystrophy Ophthalmology 2012;119:1522–9

45 Rudolph M, Laaser K, Bachmann BO, et al Corneal higher-order aberrations after Descemet’s membrane endothelial keratoplasty Ophthalmology 2012;119:528–35

46 Patryn E, van der Meulen IJ, Lapid-Gortzak R, et al Intraocular lens opacifi cations in Descemet stripping endothelial keratoplasty patients Cornea 2012;31:1189–92

47 Fellman MA, Werner L, Liu ET, et al Calcifi cation of a hydrophilic acrylic intraocular lens after Descemet-stripping endothelial keratoplasty: case report and laboratory analyses

J Cataract Refract Surg 2013;39:799–803

48 Oberg TJ, Sikder S, Jorgensen AJ, et al Topical-intracameral anesthesia without preoperative mydriatic agents for Descemet-stripping automated endothelial keratoplasty and phacoemulsi-

fi cation cataract surgery with intraocular lens implantation J Cataract Refract Surg 2012;38:384–6

49 Fang JP, Hamill MB Descemet’s stripping endothelial keratoplasty under topical anesthesia

J Cataract Refract Surg 2007;33:187–8

50 Price FW, Price MO DSEK: what you need to know about endothelial keratoplasty Thorofare: SLACK Incorporated; 2009

51 Dirisamer M, Dapena I, Ham L, et al Patterns of corneal endothelialization and corneal ance after descemet membrane endothelial keratoplasty for Fuchs endothelial dystrophy Am

54 Mehta JS, Hantera MM, Tan DT Modifi ed air-assisted descemetorhexis for Descemet- stripping automated endothelial keratoplasty J Cataract Refract Surg 2008;34:889–91

55 Melles GR, Ong TS, Ververs B, et al Descemet membrane endothelial keratoplasty (DMEK) Cornea 2006;25:987–90

56 Price MO, Price Jr FW Descemet’s membrane endothelial keratoplasty surgery: update on the evidence and hurdles to acceptance Curr Opin Ophthalmol 2013;24:329–35

© Springer India 2016

S Jacob (ed.), Mastering Endothelial Keratoplasty,

DOI 10.1007/978-81-322-2821-9_2

Endothelial Keratoplasty in the Setting

of a Dislocated Intraocular Lens (IOL)

Paul M Phillips , Vipul C Shah , and Valliammai Muthuappan

Contents

2.4 Performing the Endothelial Keratoplasty After an IOL Exchange or Repositioning 33

2.1 Introduction

Endothelial keratoplasty (EK) has surpassed penetrating keratoplasty (PK) as the gical standard of care for patients with endothelial failure Worldwide, the most com-mon indication for EK is Fuchs endothelial dystrophy (FED) The second most common is “post-cataract edema,” often referred to as pseudophakic bullous kera-topathy (PBK), which accounts for over 8,000 transplants performed for endothelial failure a year in the United States [ 1 ] While classically the term PBK indicates

Electronic supplementary material: The online version of this chapter (doi: 10.1007/978-81- 322- 2821-9_2 ) contains supplementary material, which is available to authorized users

P M Phillips , MD ( * ) • V Muthuappan , MD

Department of Ophthalmology , Sightline Ophthalmic Associates ,

2591 Wexford Bayne rd, Suite 104 , Sewickly , PA 15143 , USA

e-mail: paulphillipsmd@gmail.com ; vallim@gmail.com

V C Shah , MD

Department of Ophthalmology , Charlotte Eye Ear Nose & Throat Associates, PA ,

6035 Fairview Rd , Charlotte , NC 28210 , USA

e-mail: vshah@ceena.com

damage of the endothelium as a direct result of a poorly positioned or dislocated ocular lens (IOL), the term is now often used in any pseudophakic patient with cor-neal decompensation Regardless of the terminology, the corneal surgeon is likely to encounter patients with dislocated lenses who also require corneal transplantation There are now numerous published articles discussing the challenges and com-plications, as well as the good outcomes, that can be achieved when EK is per-formed in complex situations such as corneal failure in eyes with anterior chamber lenses, with anterior chamber vitreous present, after previous PK, and in eyes with previous trabeculectomies and glaucoma drainage devices (GDD) [ 2 15 ] There are also a few studies that have addressed the potentially good outcomes that can be achieved with the secondary placement of IOLs, either with lens exchange or in the setting of aphakia, combined or sequentially treated with EK [ 3 , 9 , 15 , 16 ] To date, the outcomes of EK combined with repositioning of dislocated lenses have not been directly addressed in any published papers The corneal surgeon will face the chal-lenge of an eye with a dislocated lens and corneal decompensation The goal of this chapter is to highlight the complexities of such eyes as well as strategies to consider

intra-in the evaluation and treatment of such patients

2.2 Preoperative Assessment

2.2.1 Assessing the Status of the IOL

The evaluating physician must fi rst answer a few questions about the status of a dislocated lens The fi rst question to answer is: Has the dislocated lens caused the endothelial failure, or is the edema unrelated? Lenses designed for positioning in the posterior chamber are rarely tolerated when placed in the anterior chamber and efforts should be made to reposition these lenses (Fig 2.1 ) However, the most com-mon “dislocated” lens that will lead to corneal decompensation is that of a poorly positioned anterior chamber lens When not properly sized and positioned, anterior chamber lenses will lead to endothelial trauma and eventually endothelial failure [ 17 – 19 ] While the temptation may be to immediately implicate any anterior cham-ber lens as the cause of corneal failure, this is not always the case Well-fi tting ante-rior chamber lenses may not be damaging to the endothelium [ 20 ] It is important to realize that most commonly an anterior chamber lens is placed as a result of a “trau-matic” situation, such as after a true trauma to an eye requiring surgery, as a result

of a “traumatic” cataract surgery or possibly after multiple previous surgeries, which resulted in a lack of proper capsular support It may be the previous intraocular manipulations that led to endothelial damage and subsequent corneal failure Some clues to the etiology of endothelial failure lie in the history alone A patient who has had successful vision rehabilitation with the presence of a stable anterior chamber lens for many years may simply require replacement of the endothelium leaving the anterior chamber lens in place Multiple studies have demonstrated the success of such surgery by means of deep lamellar endothelial keratoplasty (DLEK), Descemet’s stripping (automated) endothelial keratoplasty (DSEK/DSAEK), and more recently by Descemet’s membrane endothelial keratoplasty (DMEK) [ 4 , 9 , 21 ,

c

d b

Fig 2.1 A 70-year-old with anterior dislocated three-piece lens and corneal decompensation: ( a ) Presurgical image of eye ( b ) Haptic is mobilized and repositioned posterior to iris into ciliary sulcus in front of remnant anterior capsule ( c ) 10-0 prolene McCannal suture passed to close large iris defect ( d ) McCannal suture is tied closing the iris defect ( e ) Image of eye prior to performing

EK ( f ) Image of eye at completion of EK

22 ] Since it may not always be obvious, there are clues that can be used to mine if a lens is “dislocated” or otherwise poorly fi t for the eye The use of anterior segment imaging by ultrasound, optical coherence tomography, or Schiempfl ug imaging to evaluate appropriate anterior chamber depth and positioning of a lens may be helpful However, such technology is not always necessary or available, and

deter-the surgeon can simply look for clinical signs Frank dislocation of “iris claw” style lenses or pseudophakodonesis may be fairly obvious Other more subtle signs that will indicate the need for lens removal include the presence of anterior or posterior synechiae, iris atrophy or defects, chronic iritis, cystoid macular edema (CME), or the development of glaucoma (Fig 2.2 ) In these cases, removal of the lens with placement of a secondary posterior chamber fi xated lens will be necessary and EK

in these settings has been proven successful [ 3 , 6 , 8 , 9 , 15 ]

Alternatively, a corneal surgeon may be faced with endothelial failure in the ting of a dislocated posterior chamber lens While this situation is less common, the question of whether the lens is the cause of the corneal failure cannot be dismissed For instance, most modern-day posterior chamber lenses are designed to be placed within the capsular bag While some lenses (usually three-piece) can also be posi-tioned within the ciliary sulcus, many lenses (usually one-piece) if dislocated out of the bag or placed primarily in the sulcus will result in iris chafi ng, which can lead to uveitis, hyphema, and glaucoma (UGH) syndrome and may eventually cause endo-thelial damage [ 23 – 27 ] Anterior segment ultrasound can be helpful in identifying whether a poorly positioned posterior chamber lens is causing uveitis [ 23 , 24 , 28 , 29 ] However in the setting of a dislocated one-piece style lens that is entirely or partially positioned in ciliary sulcus, the assumption should be that this lens is the cause [ 25 ,

set-27 ] As with dislocated anterior chamber lenses, dislocated posterior chamber lenses leading to UGH syndrome must be replaced or possibly repositioned prior to or dur-ing any surgery performed to treat the corneal endothelial failure (Fig 2.3 )

Once it has been determined that the dislocated lens is not the cause of chronic disease or the endothelial failure, further questions must be asked to determine if a

Fig 2.2 ( a ) A 65-year-old female with a poorly fi t (dislocated) anterior chamber lens with

entrap-ment of haptic into iris, resulting in anterior synechia and an irregular pupil ( blue arrows ) The patient developed chronic iritis, glaucoma, and corneal decompensation Tube shunt surgery ( white

arrow ) was required for pressure control Dashed circle highlights location of lens optic ( b ) One

week postoperative: vitrectomy, anterior chamber IOL exchange with scleral sutured lens, and

iridoplasty combined with DSAEK Note blue arrows highlight the edge of the DSAEK graft White arrow points to sight of iridoplasty suture

b

Fig 2.3 ( a ) A 72-year-old with traumatic mydriasis and UGH syndrome due to a complicated

cataract extraction and placement of a one-piece style lens (Acyrsof IQ lens, Alcon Labs, Fort Worth, TX) lens within the ciliary sulcus Note enlarged image of iris defect in location of iris

chafi ng from the square edge haptic Arrows point to the signifi cant microhyphema present ( b )

One week post IOL exchange with placement of three-piece style lens (Acrysof MN60AC, Alcon Labs, Forth Worth, TX) in the sulcus and iridoplasty Corneal edema recovered without need for

EK procedure

dislocated lens will need to be repositioned or replaced Is the lens dislocated and decentered enough to cause visual impairment? Many lenses can be moderately dis-located without signifi cantly affecting the vision (Fig 2.4 ) However, if a lens is only mildly to moderately decentered, but is not stable, it must be addressed The most common forms of EK performed today (DSEK/DSAEK and DMEK) all involve fairly signifi cant intraocular manipulation, including the injection of air or gas, which could lead to the dislocation of an unstable IOL, resulting in further com-plications with signifi cant comorbidity [ 30 ] Once again, ultrasound imaging can potentially aid in determining the stability of a lens, but clinical fi ndings are often suffi cient The presence of signifi cant pseudophakodonesis or posterior tilting of the lens in the supine position, as well as the absence of suffi cient capsular or zonular support, is enough to warrant concern for the potential of complete dislocation of a lens during or after EK surgery Such lenses need to be stabilized or replaced.

a

b

Fig 2.4 A 60-year-old with a history of status post-complex cataract surgery ( a ) Dislocated but

stable plate haptic lens/bag complex, with iris trapped within cataract wound and corneal

decom-pensation ( b ) Iridoplasty is performed using McCannal suture and without manipulation of lens ( c ) Post-iridoplasty prior to DSAEK ( d ) Eye at completion of DSAEK surgery

Whenever possible, it is important that the surgeon also determine the make and model of the dislocated lens It has recently been shown that hydrophilic acrylic lenses will opacify when subjected to air or gas injections during EK surgery [ 31 –

34 ] (Fig 2.5 ) The surgeon should consider removing such lenses when dislocated rather than simply repositioning and stabilizing the lens Three-piece lenses and other one-piece models with thin “arm” style haptics may be reasonably easy to secure with one of a number of suturing techniques highlighted later Some models, such as plate haptic lenses, are more diffi cult to deal with In these cases, if the cap-sular bag complex is signifi cantly fi brotic or there is a capsular tension ring present,

it may be used to fi xate the lens to the sclera If this is not the case, the haptics are

a

b

Fig 2.5 A one-piece hydrophilic acrylic IOL, opacifi ed after being exposed to intracameral tion of air during a DSAEK surgery: ( a ) Clinical photograph of opacifi ed lens post-DSAEK White arrows highlight area of signifi cant lens opacifi cation ( b ) Light photomicrograph of explanted

injec-IOL showing deposits on anterior surface/subsurface of the injec-IOL (Images supplied by Liliana Werner Reproduced/Reprinted from: Werner L et al [ 31 ], with permission from Elsevier)

not easily secured with suture and scleral fi xation may not be a good option Removal and replacement of these lenses may be necessary.

Another critical aspect of the presurgical evaluation is to consider the important eye structures that will potentially be used to secure a lens The eye must be evalu-ated carefully to determine if there is signifi cant iris atrophy, profound scleral thin-ning, or previous glaucoma surgery (trabeculectomies or GGD) that will preclude the use of certain fi xation techniques The surgeon should strive to understand and ideally master multiple IOL fi xation techniques to be fully prepared to deal with the inability to perform one given procedure in a certain setting

Finally, the amount of corneal edema present should be considered Profound bullous edema may limit the view to the anterior and posterior segments and may limit the surgeons ability to perform certain IOL repositioning maneuvers safely or prevent repositioning of a lens altogether In such cases it may be most prudent to perform a PK, which would enable better visualization of the dislocated IOL and more easily combine the transplant with IOL stabilization or exchange

2.3 Determining a Surgical Plan

Once a complete preoperative evaluation is performed, a surgical plan must be oped that provides the best chance for visual recovery with the least risk of both short- and late-term complications The surgeon must consider several options regarding a dislocated IOL, which include no intervention, IOL repositioning, or IOL exchange The decision must also be made whether to perform the EK as a com-bined procedure with the lens intervention, or as a staged procedure at a later date

devel-2.3.1 No IOL Intervention

If a lens is stable and dislocated, there may be no need to manipulate it A lens that is

fi brosed within a bag with only local zonular dehiscence may be left alone (Fig 2.4 ) The challenge for the surgeon is to not only determine the stability of the lens, but also the likelihood that the lens dislocation is related to any concurrent visual complaint This certainly may be diffi cult in the setting of a patient with signifi cant corneal edema and/or other comorbidities such as iris loss, iris defects, or retinal disease

2.3.2 Repositioning of Dislocated IOLs

In certain situations, dislocated lenses may be repositioned rather than replaced using one of a number of surgical techniques It is important that a repositioned lens

is properly secured within the eye prior to a combined or staged EK surgery to avoid

the possibility of intraoperative dislocation of a lens When a salvageable IOL is still in the capsular bag, forming an IOL-in-the-bag complex, it may be possible to reattach the complex to the scleral wall Another situation involves a sulcus IOL that has lost its support In this case, it may be possible to directly suture such an IOL to the sclera or iris The signifi cant advantage of retaining the primary lens is avoiding more signifi cant intraocular manipulations that may lead to vitreous prolapse or even more severe secondary complications such as retinal detachments or choroidal hemorrhage [ 35 ] Additionally, reattachment techniques may avoid the need for larger limbal incisions involved with removal of an IOL

The IOL-in-the-bag complex can be reattached to the scleral wall via numerous suturing techniques One technique involves an initial stab incision in the cornea, followed by the passage of a double-armed suture through the incision with one arm over and one arm under the dislocated lens haptic The needles are passed through the sulcus, exiting through the sclera, and the knot is buried into a scratch incision in the sclera, under a scleral fl ap or possibly through a “Hoffman” pocket [ 36 ] It can

be diffi cult to penetrate the fi brosed capsular complex with the needle This ver can be aided by the use of a “nesting” needle such as a 27-gauge hypodermic needle (Fig 2.6 ) Though all suture materials may break down over time, it is recom-mended to use a more “non-degradable” 9-0 propylene, or 8-0 Gore-Tex suture [ 35 ,

maneu-37 ] While 10-0 prolene suture can be effectively used to secure a lens to the scleral, studies have shown that this material will form cracks and degrade over time [ 38 ] Certain IOLs can also be attached to the iris The traditional approach is via a McCannel suture, or a sliding Siepser knot [ 34 – 37 ] The suture must be passed

Fig 2.6 A 54-year-old male with a history of traumatic cataract status post-cataract extraction He

presented with a dislocated IOL–capsular bag complex and corneal decompensation ( a ) Preoperative image of dislocated IOL ( b ) The extent of the dislocation is more evident after place- ment of a Malyugin ring (MicroSurgical Technologies, Redmond, WA) ( c ) A 27-gauge hypoder-

mic needle is used to aid the passage of a 9-0 prolene suture through the capsular bag and under

the haptic of the IOL and externalized through a “Hoffman” pocket ( d ) A similar second pass with the 9-0 prolene suture is made, this time over the haptic ( e ) The needles are cut and the suture is retrieved through the pocket ( f ) The suture is then tied bringing the lens into good stable centra- tion, the tails are cut and the knot is buried within the pocket ( g ) The DSAEK surgery is per- formed ( h ) The graft is well attached at postoperative day 1